Our objective is two fold: 1. Characterization of those materials, cellular and acellular, secretory and foreign, which accumulate in airways of man in response to environmental pollutants, primarily crystalline silicates. 2. Using experimental animals, to delineate the inflammatory and destructive sequelae which results in lungs from inhalation of the identifiable environmental crystals and their adsorbed organic pollutants. The method used for obtaining such material from patients known to be exposed to dusts is bronchoalveolar lavage. Methods to be used in this study include morphologic, cytologic, crystalographic, elemental, and biochemical analyses.